Bookholder

ABSTRACT

An improved bookholder utilizing a novel spring clamp biased against the support surface of the holder, the clamp including a spring separate from the holddown arm so as to utilize a different gauge wire. In one embodiment the spring contains a coiled extension of the arm, tension being developed in the spring by means of a straight extension of the arm pressing against an axially extending arm of the coil spring. In the other embodiment, a core is contained by the spring and has at one end a camming surface for engagement by an extension of the holddown arm, the extension in this case not curving to form a coil but only a portion of a complete circle. In both embodiments, an end cap is centered within the housing containing the spring mechanisms, the cap including a clamping lip to assist in attaching the housing to the support surface of the bookholder.

United States Patent Henry R. Dickinson, 1 11 222 Parkhurst, SpringLake, Mich. 49%6 [72] Inventor [2i] Appl. No. 863,549 [22] Filed Oct. 3,1969 [45] Patented Sept. 7, i97l [54] BOUKHOLDER FOREIGN PATENTS 10,2094/1913 Great Britain AlBS'll'll MCT: An improved booltholder utilizing anovel spring clamp biased against the support surface of the holder, theclamp including a spring separate from the holddown arm so as to utilizea different gauge wire. In one embodiment the spring contains a coiledextension of the arm, tension being developed in the spring by means ofa straight extension of the arm pressing against an axially extendingarm of the coil spring. In the other embodiment, a core is contained bythe spring and has at one end a camming surface for engagement by anextension of the holddown arm, the extension in this case not curving toform a coil but only a portion of a complete circle. In bothembodiments, an end cap is centered within the housing containing thespring mechanisms, the cap including a clamping lip to assist inattaching the housing to the support surface of the booltholder.

PATENTED ssh 719m SHEET 1 OF 2 FIG] 5 16. 1

HENRY R. DICKINSON III FIG. .9 BY

ATTORNEYS PATENTEUSEP 119m 7 3,603,554

SHEET 2 0F 2 INVEHTOR HENRY R. DICKINSON ID:

ATTORNEYS BOOKIHIOLDIER BACKGROUND OF THE INVENTION Prior art bookholders, such as the type disclosed in my U.S. Pat. No. 2,721,417,issued Oct. 25, 1955, have generally performed satisfactorily, butnevertheless have evidenced the need for some improvement, particularlyin connection with the spring clamp. Specifically, the manner in whichthe spring clamp was mounted in these devices such as in my aforesaidpatent resulted in a spring clamp which, in order to provide a thickenough gauge in the holddown portion, also provided too much tension inthe spring due to the strength present in the thick diameter wire.

Some very old construction of bookholders have provided springsutilizing a different wire thickness than that utilized in the holddownarm, but they have been characterized by complex and unsightlyconstructions. Further, such constructions have been almost impossibleto repair, or for example, replace the spring, should it wear out. Anexample of such an old construction is the disclosure of U.S. Pat. No.816,380.

SUMMARY OF THE INVENTION The invention relates to an improved bookholderutilizing a novel spring biasing of the holddown arm. Specifically, theinvention is utilized in a bookholder having a support surface and aspring clamp means for removably clamping an object against the surface,the clamp means including an elongated holddown arm having a free endextending over the support surface, its other end being supported forproviding a biasing force for the holddown arm. The improvementconstituting the invention comprises the holddown arm including at itssupported end at least a portion of a convolution, the center of whichis the axis about which the holddown arm is biased. A spring meansseparate from the convoluted portion of the arm is of a smaller gaugethan the holddown arm, and formed into convolutions the center axis ofwhich is coincident with the center of the convolution of the holddownarm. Means operably interconnect the convoluted portion of the arm andthe spring means whereby the spring means provides the biasing for theholddown arm.

A support means is provided for the end of the holddown arm oppositefrom the end extending over the surface, including a tubelike housinghaving open ends, the opposite end of the holddown arm being located inat least one of the open ends; a cap is fitted over the open end inwhich the am is located, the cap including a slot for receiving theportion of the arm which extends over the surface and also forpermitting movement of the arm against the biasing force; and a flangeis provided on the cap for securing the cap to the support so as to aidin securing the housing to the support.

Accordingly, it is an object of the invention to provide an improvedbookholder wherein the holddown arm utilizes a sufficiently thick wirefor support purposes without making the clamp thereby unduly stiff inits spring action.

It is another object of the invention to provide an improved bookholderof the above character wherein the parts can be readily disassembled soas to remove for replacement or repair the coil spring.

It is a further object to provide an improved bookholder of the abovecharacter wherein the ends of the housing of the spring areself-attaching to the support surface so as to allow attaching screws tobe moved away from the spring mechanism.

It is a related object of the invention to provide a bookholder of theabove character which is simple to manufacture and assemble.

It is still another object of the invention to provide a housing for thespring mechanism which also functions as a supporting ledge.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a booksupport constructed in accordance with the invention;

FIG. 2 is an exploded elevational view of a portion of a spring clampconstructed in accordance with the invention;

FIG. 3 is an end elevational view of the device illustrated in FIG. 2,in combination with the housing of the spring and the bookholder;

FIG. 4 is a plan view taken generally along the line IV-IV of FIG. 3,with the housing and bookholder eliminated;

FIG. 5 is a front elevational view, partly in section, taken along theline VV of FIG. 1 and illustrating still another embodiment of theinvention;

FIG. 6 is a perspective view of a portion of the spring clampillustrated in FIG. 5',

FIG. 7 is an end elevational view of the device illustrated in FIG. 6;

FIG. 8 is a fragmentary plan view of the device illustrated in FIG. 7;

FIG. 9 is a fragmentary exploded perspective view of the spring clampillustrated in FIG. 5;

FIG. 10 is an elevational view of an end cap utilized in either of thetwo embodiments of the invention; and

FIG. ll is a plan view of the cap shown in FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention relates to animproved bookholder of the type disclosed in my U.S. Pat. No. 2,721,417.Although the in vention is disclosed with reference to such an improvedbookholder, it will be readily appreciated that it is not limited tosuch a use but can be incorporated in any device requiring a springclamp, such as a clip board.

As in the case of my aforesaid patent, the bookholder 12 comprises asupporting surface 114! to which is hinged at the top a mounting plate16 which has boltholes ll7 therein. A support arm (not shown) isutilized to hold the supporting surface M in a desired position withrespect to the mounting plate 16. A housing 18 is formed from a tubehaving a rectangular or square cross section and is attached to thelower edge of the supporting surface 14. By this bookholder, the pagesare held open at a desired page location by means of holddown arms 20,spring biasing means being included within the housing 18 for biasingthe holddown arms. against the pages of the book (not shown). Theholddown arms are conveniently, but not necessarily, formed from wirehaving a diameter of one-eighth inch.

In accordance with one aspect of the invention, the holddown arms 20 arebiased by a coil spring 30 (FIG. 2) formed separately from the holddownarms and of a wire gauge which is smaller in gauge than the gauge of theholddown arms. The smaller diameter of the coil spring 30 means that thebiasing force developed by the spring will be less than it would be ifthe same diameter as the holddown arm was utilized, thus avoiding theundesirable stiffness that has been present in previous devices. To holdthe coil spring 30 in position so as to resist flexing in the directionshown as counterclockwise in FIG. 3, the end 32 of the coil spring isextended straight tangentially away from the coil spring, therebyproviding a surface which abuts against the inside of the tube housing18. The biasing force of the coil spring 30 is transmitted to holddownarm 20 in a clockwise direction from end 32 and it projects parallel tothe axis of the coil spring so as to be removably contacted by theportion 3d of the holddown arm 20 when the coil spring is positioned innested relationship to the holddown arm. Specifically, the holddown arm20 has a straight extension 38 bent away from the holddown arm tointerconnect the arm with the coil spring. The arm 20 culminates inconvolutions 4,0 which fit into and are contained within the coil spring39. Thus, when the two parts are assembled, any tendency to" move theholddown arm 20 counterclockwise as shown in FIG. 3 causes the armportion 3% to press against the ear 34.

To allow the parts of the spring assembly to be readily disassembled andto allow the removal of the coil spring 30, the portion 38 is notphysically connected to ear 34 but rather removably contacts and pressesagainst it.

The spring clamp comprising the holddown arm 20, its extension 40, andthe coil spring 30 are held in their assembled relationship by an endcap 50 (FIG. placed over the ends of the housing 18 and attached theretoby means ofa screw inserted into the opening 52. The mounting of housing18 on the support surface 14 is assisted by the end cap 50 whichincludes a lip 54 extending around to the back side of the supportsurface 14 in a clamping relationship. To provide clearance for theholddown arm 20, a groove 58 is formed in one side of the end of cap 50(FIG. 11). Because the car 34 projects outwardly beyond the end of thecoil extension 40 of the holddown arm 20, an accommodating cutout 60 isprovided in the back 62 of the end cap, the cutout being shaped as aportion of a circular path inasmuch as the ear moves in such a circularpath. To center during assembly the end cap 50 in the tube comprisingthe housing 18, locator pins 64 are formed intcgrally with the frontsurface 66 of the end of cap 50. The pins are spaced apart at distancesless than the interior dimensions of the housing 18.

Because of the support provided by the lip 54 on the end cap 50, thescrews 70 providing the main attachment of the housing 18 to thesupporting surface 14 can be moved to a position interior of the ends ofthe housing 18, thus providing clearance by the screw 70 of the springclamp mechanism (see FIG. 5).

To further simplify manufacturing and thereby reducing the cost, thehousing 18 is extruded as a single piece tube with its rectangular crosssection which because of its hollowness, easily contains the springmechanisms for the holddown arms 20.

It will be appreciated that, when assembled, the housing 18 acts as aledge to support whatever is clamped to the surface 14.

FIGS. 5 through 9 illustrate an alternate embodiment of the inventionwherein the coil extension 40 of the holddown arm has been eliminated inlieu of a core 92 which fits within the coil spring 30a and which isengaged by the holddown arm a. Parts similar to those described inconnection with the previous embodiment bear the same reference numeralsto which the distinguishing suffix a has been added. Thus, as shown inFIG. 5, housing 18a contains a coil spring 30a, one and 32a of whichextends straight tangentially away from the coil spring so as to providea gripping surface when in contact with the surface 90 of the housing18a preventing the coil spring from freely turning. The opposite end 34aof a coil spring extends as a chord across the coil spring and engagesthe core 92 on a flat surface 94 provided therein. To retain the springin proper axial position, a shoulder 95 is formed at the end of thecore. Thus, any tendency of the core 92 to rotate counterclockwise asshown in FIG. 9 causes the end 34a to rotate in the same direction,thereby tensioning the spring 30a in view of the locked position of theend 32a. To turn the core 92 in such counterclockwise direction, thecore includes means for attaching the holddown arm 20a to the core, themeans including an arm support end 98 at one end of the core. Thesupport end 98 comprises a protrusion 100 which is either formedintegrally with the core 92 or is attached thereto such as by a screw.The protrusion has a curved surface 104, the radius of curvature ofwhich matches the radius of curvature of a convolution portion 40a ofthe holddown arm 20a. As in the previous embodiment, the convolutedportion 40a is joined to the actual holddown arm 20a by means of astraight portion 38a bent at an angle to the holddown arm 20a. Theportion 40a, unlike the previous embodiment, does not include severalconvolutions but rather forms a portion ofa convolution ending at point106. The surface 104 ends in a flat portion 108 against which thestraight portion 38a cams when the holddown arm 20a rotatescounterclockwise as shown in FIG. 9, thereby causing the core 92 torotate in the same direction so as to set up the tension in the spring30a.

The core 92 can be molded as a plastic unit with the shape as shown, orit can be machined to have the desired surfaces.

As in the previous embodiment, an end cap 50a is utilized to enclose thespring mechanism, the end cap utilizing a lip 54a to assist in holdingthe housing 180 on the support surface of the bookholder. The end cap501: is firmly attached to the housing 180 by means of a screw 110 whichis threaded into the tab 112 bent upwardly from one surface of the tubeforming the housing. Thus, the end cap 500 is in all respects identicalto the end cap 50 disclosed in the previous embodiment.

It will be readily appreciated that when the parts are assembled asshown in either FIG. 1 or FIG. 5, with the holddown arm pressing againstthe support surface of the bookholder and, in the case of FIG. 5, theextension 40a surrounding the curved camming surface 104, the holddownarm has been rotated counterclockwise so as to position it on thesupport surface, thereby setting up tension in the spring so as to holdeven the thinnest of books on the support surface. Because of theability of the coil spring 30 or 30a to bend perpendicularly to its axisto some extent, the assembly can be accomplished with this preset amountof tension in the spring.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows.

1. In a combination of a support having a surface and a spring clampmeans for removably clamping an object against said surface, said springclamp means including an elongated holddown arm having a free endextending over said surface, its other end being supported to provide abiasing force for said holddown arm; the improvement comprising asupport means for said other end of said holddown arm including atubelike housing having open ends, said other end of said holddown armlocated in at least one of said open ends; and a cap fitted over theopen end in which said arm is located; said cap including a slot forreceiving the portion of the arm which extends over said surface andalso for permitting movement of said arm against said biasing force; anda flange on said cap for securing said cap to said support therebyproviding a means for at least aiding in the securing of said housing tosaid support.

2. The improved combination as defined in claim 1, wherein said capincludes means for centering said cap with respect to said housing.

3. The improved combination as defined in claim 2, wherein saidcentering means includes a plurality of locator pins spaced apart atdistances less than the interior dimensions of said housing.

4. The improved combination as defined in claim 3, wherein said biasingforce is provided by a coil spring contained within said housing.

5. The improved bookholder as defined in claim 4, wherein said capincludes a cutout shaped as a portion of a circular path, said cutoutaccommodating a portion of said spring.

6. The improved combination as defined in claim 1, wherein said housingis a one-piece extrusion having a rectangular cross section.

1. In a combination of a support having a surface and a spring clampmeans for removably clamping an object against said surface, said springclamp means including an elongated holddown arm having a free endextending over said surface, its other end being supported to provide abiasing force for said holddown arm; the improvement comprising asupport means for said other end of said holddown arm including atubelike housing having open ends, said other end of said holddown armlocated in at least one of said open ends; and a cap fitted over theopen end in which said arm is located; said cap including a slot forreceiving the portion of the arm which extends over said surface andalso for permitting movement of said arm against said biasing force; anda flange on said cap for securing said cap to said support therebyproviding a means for at least aiding in the securing of said housing tosaid support.
 2. The improved combination as defined in claim 1, whereinsaid cap includes means for centering said cap with respect to saidhousing.
 3. The improved combination as dEfined in claim 2, wherein saidcentering means includes a plurality of locator pins spaced apart atdistances less than the interior dimensions of said housing.
 4. Theimproved combination as defined in claim 3, wherein said biasing forceis provided by a coil spring contained within said housing.
 5. Theimproved bookholder as defined in claim 4, wherein said cap includes acutout shaped as a portion of a circular path, said cutout accommodatinga portion of said spring.
 6. The improved combination as defined inclaim 1, wherein said housing is a one-piece extrusion having arectangular cross section.